JP6631809B2 - Film capacitor - Google Patents

Description

  The present invention relates to a film capacitor having a resin film having excellent heat resistance, withstand voltage characteristics and workability as a dielectric film.

A film capacitor is a device having a structure in which dielectric films and metal layers are alternately arranged, and is capable of storing electric charges.
In recent years, as film capacitors have been reduced in size and increased in capacity, they have become easier to generate heat during driving. For this reason, a resin film used as a dielectric film of a film capacitor is required to have better heat resistance.
Also, in order to reduce the size of film capacitors, it has been required to make the dielectric film thinner. However, when the dielectric film is made thinner, the withstand voltage characteristics (the characteristic that the insulating state is maintained even under high voltage). ) And workability (the property that a film capacitor can be stably manufactured even on an industrial production scale).

  In connection with the present invention, Patent Document 1 describes a film capacitor using a film formed by molding a hydride of a norbornene-based ring-opening polymer or the like.

JP-A-11-60971

  As described in Patent Document 1, a film made of a hydrogenated norbornene-based ring-opening polymer is suitable as a dielectric film of a film capacitor. However, in recent years, as the required performance of the film capacitor has been increased, there has been a demand for a film capacitor having better heat resistance, withstand voltage characteristics, and workability.

  The present invention has been made in view of the related art described above, and has as its object to provide a film capacitor having, as a dielectric film, a resin film having excellent heat resistance, withstand voltage characteristics, and workability.

  The present inventors have intensively studied a resin film used as a dielectric film of a film capacitor in order to solve the above problems. As a result, after stretching an unstretched film using a crystalline hydrogenated dicyclopentadiene ring-opening polymer, the stretched film is obtained by heat treatment, and has a softening point, heat shrinkage, tan δ, The present inventors have found that a resin film having a specific coefficient of static friction within a specific range is excellent in all of heat resistance, withstand voltage characteristics, and workability, and have completed the present invention.

Thus, according to the present invention, the following film capacitors [1] and [2] are provided.
[1] A film capacitor having a dielectric film and a metal layer, wherein the dielectric film is subjected to a stretching treatment of an unstretched film using a crystalline hydrogenated dicyclopentadiene ring-opening polymer, A resin film obtained by performing a heat treatment, wherein the resin film has a softening point of 250 to 320 ° C., a heat shrinkage of 0.01 to 5.0% when heated at 200 ° C. for 10 minutes, and a tan δ of 0. A film capacitor comprising a resin film having a 0.0001 to 0.0010 and a static friction coefficient of 0.01 to 1.00.
[2] The resin film, after stretching the unstretched film under the conditions of a stretching temperature of 95 to 135 ° C., a stretching ratio of 1.2 to 10 times, and a stretching speed of 100 to 30,000 mm / min, The film capacitor according to [1], which is obtained by performing heat treatment at a heating temperature of 150 to 240 ° C. and a heating time of 0.1 to 600 minutes.

  ADVANTAGE OF THE INVENTION According to this invention, the film capacitor which has a resin film excellent in all of heat resistance, a withstand voltage characteristic, and workability as a dielectric film is provided.

  The present invention is a film capacitor having a dielectric film and a metal layer.

(Dielectric film)
The dielectric film constituting the film capacitor of the present invention is a resin film obtained by stretching a non-stretched film using a crystalline hydrogenated dicyclopentadiene ring-opening polymer and then subjecting it to a heat treatment. The resin film has a softening point of 250 to 320 ° C., a heat shrinkage of 0.01 to 5.0%, a tan δ of 0.0001 to 0.0010, and a static friction coefficient of 0.01 to 1.00. (Hereinafter may be referred to as “resin film (I)”).

The “hydrogenated dicyclopentadiene ring-opening polymer” used in the production of the resin film (I) is a hydrogenated dicyclopentadiene ring-opening polymer, and has a melting point obtained by performing a stretching treatment or the like. Thus, a film-shaped molded article having the same is obtained.
Examples of the hydrogenated crystalline dicyclopentadiene ring-opening polymer include, for example, hydrogenated products of a ring-opening polymer of dicyclopentadiene having syndiotactic stereoregularity described in JP-A-2006-52333. No.
Hereinafter, the “ring-opened polymer of dicyclopentadiene having syndiotactic stereoregularity” is referred to as “polymer (α)”, and the “hydrogenated product of polymer (α)” is referred to as “polymer (β)”. There is that.

  The polymer (α) is obtained by ring-opening polymerization of dicyclopentadiene. The dicyclopentadiene used includes an endo-form and an exo-form stereoisomer, both of which can be used as a monomer. One of the isomers may be used alone, or the endo-form may be used. A mixture of isomers in which the exo form and the exo form are present in an arbitrary ratio may be used. However, from the viewpoint of increasing the crystallinity of the polymer (β) and making the heat resistance particularly good, it is preferable to increase the ratio of one stereoisomer. For example, the ratio of the endo-form or exo-form is preferably 80% or more, more preferably 90% or more, and particularly preferably 95% or more. The stereoisomer whose proportion is increased is preferably an endo-isomer from the viewpoint of ease of synthesis.

The polymer (α) may have a repeating unit other than the repeating unit derived from dicyclopentadiene as long as it gives the polymer (β) having crystallinity. Such a polymer (α) can be produced by ring-opening copolymerization of dicyclopentadiene and a monomer other than dicyclopentadiene.
Examples of monomers other than dicyclopentadiene include polycyclic norbornene compounds other than dicyclopentadiene, bicyclic norbornene compounds having no ring structure fused to a norbornene skeleton, monocyclic olefins, and cyclic dienes, and Derivatives of
When these monomers are used, the amount thereof is generally more than 0% by weight and 20% by weight or less, preferably more than 0% by weight and 10% by weight or less based on all the monomers.

The catalyst used for the production of the polymer (α) is not particularly limited as long as it can produce the polymer (α) by ring-opening polymerization of dicyclopentadiene.
Examples of such a catalyst include a ring-opening polymerization catalyst containing a metal compound represented by the following formula (1) (hereinafter sometimes referred to as “metal compound (1)”) as a catalytically active component.

(Wherein M is a metal atom selected from transition metal atoms of Group 6 of the periodic table. R ¹ may have a substituent at at least one of the 3, 4, and 5 positions. phenyl group, or a group represented by -CH ₂ R ^3, R ³ is a hydrogen atom, a aryl group which may have also alkyl groups and substituents have a substituent R ² is a group selected from an alkyl group which may have a substituent and an aryl group which may have a substituent, and X is a halogen atom or an alkyl group. , An aryl group and an alkylsilyl group, L is an electron donating neutral ligand, a is 0 or 1, and b is an integer of 0 to 2. When X or a plurality of Ls are present, the plurality of Xs or the plurality of Ls may be the same as each other, It may be made to.)

  The metal atom (M) constituting the metal compound (1) is selected from transition metal atoms belonging to Group 6 of the periodic table (chromium, molybdenum, tungsten). Above all, molybdenum or tungsten is preferable, and tungsten is more preferable.

The metal compound (1) contains a metal imide bond.
R ¹ is a substituent on a nitrogen atom constituting a metal imide bond.
Examples of the substituent of the phenyl group which may have a substituent at at least one of positions 3, 4, and 5 of R ¹ include an alkyl group such as a methyl group and an ethyl group; a fluorine atom, a chlorine atom, and a bromine. A halogen atom such as an atom; an alkoxy group such as a methoxy group, an ethoxy group and an isopropoxy group; and the like, and further, a substituent in which at least two of the 3, 4, and 5 positions are bonded to each other. May be.

  Specific examples of the phenyl group which may have a substituent at at least one of positions 3, 4, and 5 include a phenyl group; a 4-methylphenyl group, a 4-chlorophenyl group, a 3-methoxyphenyl group, Mono-substituted phenyl groups such as cyclohexylphenyl group and 4-methoxyphenyl group; and disubstituted groups such as 3,5-dimethylphenyl group, 3,5-dichlorophenyl group, 3,4-dimethylphenyl group and 3,5-dimethoxyphenyl group. Substituted phenyl group; trisubstituted phenyl group such as 3,4,5-trimethylphenyl group and 3,4,5-trichlorophenyl group; 2-naphthyl group, 3-methyl-2-naphthyl group, 4-methyl-2- 2-naphthyl group which may have a substituent such as naphthyl group;

The carbon number of the optionally substituted alkyl group of R ^{3 in} the group represented by —CH ₂ R ³ of R ¹ is not particularly limited, but is usually 1 to 20, preferably 1 to 10 And more preferably 1 to 4. The alkyl group may be linear or branched. The substituent of the alkyl group is not particularly limited, and examples thereof include a phenyl group which may have a substituent such as a phenyl group and a 4-methylphenyl group; and an alkoxyl group such as a methoxy group and an ethoxy group.

Examples of the optionally substituted aryl group for R ³ include a phenyl group, a 1-naphthyl group, and a 2-naphthyl group. The substituent of the aryl group is not particularly limited, and examples thereof include a phenyl group which may have a substituent such as a phenyl group and a 4-methylphenyl group; an alkoxyl group such as a methoxy group and an ethoxy group; No.
R ³ is an alkyl group having 1 to 20 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, a hexyl group, an octyl group, and a decyl group. Is preferred.

  The metal compound (1) has three or four groups selected from a halogen atom, an alkyl group, an aryl group, and an alkylsilyl group. That is, in the formula (1), X represents a group selected from a halogen atom, an alkyl group, an aryl group and an alkylsilyl group. When two or more groups represented by X are present in the metal compound (1), those groups may be bonded to each other.

  Examples of the halogen atom for X include a chlorine atom, a bromine atom and an iodine atom. Examples of the alkyl group for X include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, a neopentyl group, a benzyl group, and a neophyl group. Examples of the aryl group for X include a phenyl group, a 4-methylphenyl group, a 2,6-dimethylphenyl group, a 1-naphthyl group, a 2-naphthyl group, and the like. Examples of the alkylsilyl group for X include a trimethylsilyl group, a triethylsilyl group, and a t-butyldimethylsilyl group.

The metal compound (1) may have one metal alkoxide bond or one metal aryloxide bond. The substituent (R ² in the formula (1)) on the oxygen atom constituting the metal alkoxide bond or the metal aryloxide bond may have an alkyl group which may have a substituent and a substituent. It is a group selected from good aryl groups. Examples of the alkyl group which may have a substituent or the aryl group which may have a substituent for R ² include the alkyl group and the substituent which may have a substituent described above for R ^3. And the same as those described as the aryl group which may have.

The metal compound (1) may have one or two electron-donating neutral ligands.
Examples of the electron-donating neutral ligand (L in the formula (1)) include an electron-donating compound containing an atom belonging to Group 14 or 15 of the periodic table.
Specific examples thereof include phosphines such as trimethylphosphine, triisopropylphosphine, tricyclohexylphosphine, and triphenylphosphine; ethers such as diethyl ether, dibutyl ether, 1,2-dimethoxyethane, and tetrahydrofuran; trimethylamine, triethylamine, pyridine, Amines such as lutidine; Of these, ethers are preferred.

As the metal compound (1), a tungsten compound having a phenylimide group (in the formula (1), a compound in which M is a tungsten atom and R ¹ is a phenyl group) is preferable, and tetrachlorotungsten phenylimide (tetrahydrofuran) Is more preferred.

  The metal compound (1) comprises an oxyhalide of a Group 6 transition metal, a phenyl isocyanate optionally having a substituent at at least one of positions 3, 4, and 5, or a monosubstituted methyl isocyanate And a neutral ligand (L) having an electron donating property and, if necessary, alcohols, metal alkoxides, and metal aryl oxides (for example, a method described in JP-A-5-345817). ). The synthesized metal compound (1) may be purified and isolated by crystallization or the like, and then used for a ring-opening polymerization reaction, or the resulting mixed solution may be used as a catalyst solution without purification. Good.

  The amount of the metal compound (1) used as the ring-opening polymerization catalyst is usually 1: 100 to 1: 2,000,000, preferably 1: 500, in a molar ratio of (metal compound (1): monomer). １ ： 1: 1,000,000, more preferably 1: 1,000 to 1: 500,000. If the amount of the catalyst is too large, it may be difficult to remove the catalyst. If the amount is too small, sufficient polymerization activity may not be obtained.

When performing ring-opening polymerization using the metal compound (1), the metal compound (1) may be used alone, or the metal compound (1) and the organometallic reducing agent may be used in combination. When the metal compound (1) and the organometallic reducing agent are used in combination, the polymerization activity may be increased.
Examples of the organometallic reducing agent include compounds of Groups 1, 2, 12, 13, and 14 of the periodic table having a hydrocarbon group having 1 to 20 carbon atoms. Of these, organolithium, organomagnesium, organozinc, organoaluminum, or organotin is preferably used, and organoaluminum or organotin is particularly preferably used.

  Examples of the organic lithium include methyl lithium, n-butyl lithium, phenyl lithium and the like. Examples of the organic magnesium include butylethylmagnesium, butyloctylmagnesium, dihexylmagnesium, ethylmagnesium chloride, n-butylmagnesium chloride, and allylmagnesium bromide. Examples of the organic zinc include dimethyl zinc, diethyl zinc, diphenyl zinc, and the like. Examples of the organic aluminum include trimethylaluminum, triethylaluminum, triisobutylaluminum, diethylaluminum chloride, ethylaluminum sesquichloride, ethylaluminum dichloride, diethylaluminum ethoxide, diisobutylaluminum isobutoxide, ethylaluminum diethoxide, isobutylaluminum diisobutoxide and the like Is mentioned. Examples of the organotin include tetramethyltin, tetra (n-butyl) tin, tetraphenyltin and the like.

  The amount of the organometallic reducing agent to be used is preferably 0.1 to 100 mol times, more preferably 0.2 to 50 mol times, particularly preferably 0.5 to 20 mol times, relative to the metal compound (1). If the amount of the organic metal reducing agent is too small, the polymerization activity may not be improved, and if the amount of the organic metal reducing agent is too large, a side reaction may easily occur.

The ring-opening polymerization reaction is usually performed in an organic solvent.
The organic solvent is not particularly limited as long as it can dissolve or disperse the desired polymer (α) or polymer (β) under predetermined conditions and does not inhibit the polymerization reaction or the hydrogenation reaction. .
Specific examples of the organic solvent include aliphatic hydrocarbons such as pentane, hexane, and heptane; cyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, ethylcyclohexane, diethylcyclohexane, decahydronaphthalene, bicycloheptane, and tricyclodecane. Alicyclic hydrocarbons such as benzene, hexahydroindene and cyclooctane; aromatic hydrocarbons such as benzene, toluene and xylene; halogen-based aliphatic hydrocarbons such as dichloromethane, chloroform and 1,2-dichloroethane; chlorobenzene, dichlorobenzene and the like Halogen-based aromatic hydrocarbons; nitrogen-containing hydrocarbon solvents such as nitromethane, nitrobenzene, and acetonitrile; ethers such as diethyl ether and tetrahydrofuran; Solvents. Among these solvents, aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, and ethers are preferably used.

The ring-opening polymerization reaction can be started by mixing the monomer, the metal compound (1), and, if necessary, the organometallic reducing agent. The order of adding these components is not particularly limited. For example, a mixture of the metal compound (1) and the organometallic reducing agent may be added to and mixed with the monomer, or a mixture of the monomer and the metal compound (1) may be added to the organometallic reducing agent. Alternatively, the metal compound (1) may be added to and mixed with a mixture of the monomer and the organometallic reducing agent.
In mixing the components, the entire amount of each component may be added at once, or may be added in multiple portions.

  The concentration of the monomer at the start of the ring-opening polymerization reaction is not particularly limited, but is preferably 1 to 50% by weight, more preferably 2 to 45% by weight, and particularly preferably 3 to 40% by weight. If the concentration of the monomer is too low, the productivity of the polymer (α) may decrease. If the concentration of the monomer is too high, the viscosity of the solution after polymerization is too high, and the subsequent hydrogenation reaction May be difficult.

An activity regulator may be added to the polymerization reaction system. The activity modifier is used for the purpose of stabilizing the ring-opening polymerization catalyst, adjusting the rate of the polymerization reaction, and adjusting the molecular weight distribution of the polymer.
The activity regulator is not particularly limited as long as it is an organic compound having a functional group, but an oxygen-containing organic compound, a nitrogen-containing organic compound, and a phosphorus-containing organic compound are preferable. Specifically, ethers such as diethyl ether, diisopropyl ether, dibutyl ether, anisole, furan, and tetrahydrofuran; ketones such as acetone, benzophenone and cyclohexanone; esters such as ethyl acetate; nitriles such as acetonitrile benzonitrile; triethylamine Amines such as pyridine, triisopropylamine, quinuclidine, N, N-diethylaniline; pyridines such as pyridine, 2,4-lutidine, 2,6-lutidine, 2-t-butylpyridine; triphenylphosphine, tricyclohexylphosphine And the like; phosphines such as trimethyl phosphate and triphenyl phosphate; phosphine oxides such as triphenyl phosphine oxide; These activity modifiers can be used alone or as a mixture of two or more.
When the activity modifier is used, its amount is not particularly limited, but may be usually selected in the range of 0.01 to 100 mol% based on the metal compound (1) used as the ring-opening polymerization catalyst.

A molecular weight modifier may be added to the polymerization reaction system in order to adjust the molecular weight of the polymer (α).
Examples of the molecular weight modifier include α-olefins such as 1-butene, 1-pentene, 1-hexene and 1-octene; aromatic vinyl compounds such as styrene and vinyltoluene; ethyl vinyl ether, isobutyl vinyl ether, allyl glycidyl ether and acetic acid. Oxygen-containing vinyl compounds such as allyl, allyl alcohol and glycidyl methacrylate; halogen-containing vinyl compounds such as allyl chloride; nitrogen-containing vinyl compounds such as acrylamide; 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, Non-conjugated dienes such as 1,6-butadiene, 2-methyl-1,4-pentadiene, 2,5-dimethyl-1,5-hexadiene; 1,3-butadiene, 2-methyl-1,3-butadiene, 2, 3-dimethyl-1,3-butadiene, 1,3-pentane Ene, conjugated dienes such as 1,3-hexadiene; and the like.
When a molecular weight modifier is used, its amount may be appropriately determined according to the target molecular weight, but is usually selected in the range of 0.1 to 50 mol% based on the monomer used.

  The polymerization temperature is not particularly limited, but is usually in the range of -78 ° C to + 200 ° C, preferably in the range of -30 ° C to + 180 ° C. The polymerization time is not particularly limited and depends on the reaction scale, but is usually in the range of 1 minute to 1000 hours.

  By performing a ring-opening polymerization reaction of a monomer containing dicyclopentadiene under the above-mentioned conditions using a ring-opening polymerization catalyst containing the metal compound (1) as described above, the polymer (α) can be efficiently produced. Can be manufactured well.

  The ratio of the racemo dyad (degree of syndiotactic stereoregularity) of the polymer (α) is usually 60% or more, preferably 65% or more, and more preferably 70 to 99%. The proportion of the racemo dyad of the polymer (α) can be adjusted by selecting the type of the ring-opening polymerization catalyst and the like.

The weight average molecular weight (Mw) of the polymer (α) is not particularly limited, but is usually from 10,000 to 100,000, preferably from 15,000 to 80,000. A polymer (β) obtained by hydrogenating a polymer (α) having a weight average molecular weight in this range is more excellent in moldability. The resin film obtained by molding the polymer (β) is more excellent in heat resistance.
The weight average molecular weight of the polymer (α) can be adjusted by adjusting the amount of a molecular weight modifier used during the polymerization and the like.
The molecular weight distribution (Mw / Mn) of the polymer (α) is not particularly limited, but is usually 4.0 or less, preferably 3.5 or less. A polymer (β) obtained by hydrogenating a polymer (α) having a molecular weight distribution in this range is more excellent in moldability.
The molecular weight distribution of the polymer (α) can be adjusted by the method of adding the monomer and the concentration of the monomer during the ring-opening polymerization reaction.
The above weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) are values in terms of standard polystyrene obtained by gel permeation chromatography using tetrahydrofuran as a solvent.

By performing a hydrogenation reaction (hydrogenation reaction of carbon-carbon unsaturated bond) of the polymer (α), the polymer (β) can be produced.
The hydrogenation reaction of the polymer (α) can be performed, for example, by supplying hydrogen into the reaction system in the presence of a hydrogenation catalyst. The hydrogenation catalyst is not particularly limited, and a homogeneous catalyst or a heterogeneous catalyst generally used for a hydrogenation reaction of an olefin compound can be appropriately used.

  Examples of the homogeneous catalyst include transition metal compounds such as cobalt acetate / triethylaluminum, nickel acetylacetonate / triisobutylaluminum, titanocene dichloride / n-butyllithium, zirconocene dichloride / sec-butyllithium, and tetrabutoxytitanate / dimethylmagnesium. A catalyst system comprising a combination of metal compounds, dichlorobis (triphenylphosphine) palladium, chlorohydridocarbonyltris (triphenylphosphine) ruthenium, bis (tricyclohexylphosphine) benzylideneruthenium (IV) dichloride, chlorotris (triphenylphosphine) rhodium And other noble metal complex catalysts.

  Examples of the heterogeneous catalyst include nickel, palladium, platinum, rhodium, ruthenium, and the like such as nickel / silica, nickel / diatomaceous earth, nickel / alumina, palladium / carbon, palladium / silica, palladium / diatomaceous earth, and palladium / alumina. Solid catalysts in which the above metal is supported on a carrier such as carbon, silica, diatomaceous earth, alumina, and titanium oxide.

  The hydrogenation reaction is usually performed in an inert organic solvent. Examples of such an inert organic solvent include aromatic hydrocarbons such as benzene and toluene; aliphatic hydrocarbons such as pentane and hexane; alicyclic hydrocarbons such as cyclohexane and decahydronaphthalene; and tetrahydrofuran and ethylene glycol dimethyl ether. Ethers; and the like. The inert organic solvent may be usually the same as the solvent used for the polymerization reaction, and the hydrogenation reaction can be carried out using a solution obtained by adding a hydrogenation catalyst to the polymerization reaction solution as it is.

The preferred reaction conditions for the hydrogenation reaction vary depending on the hydrogenation catalyst used, but the reaction temperature is usually -20 ° C to + 250 ° C, preferably -10 ° C to + 220 ° C, more preferably 0 ° C to 200 ° C. If the reaction temperature is too low, the reaction rate may be too slow, and if it is too high, side reactions may occur.
The hydrogen pressure is usually 0.01 to 20 MPa, preferably 0.05 to 15 MPa, more preferably 0.1 to 10 MPa. If the hydrogen pressure is too low, the hydrogenation rate may be too slow, and if it is too high, there is a restriction on the device in that a high pressure reactor is required. The reaction time is not particularly limited, but is usually 0.1 to 10 hours.

  The hydrogenation rate (the ratio of hydrogenated main chain double bonds) in the hydrogenation reaction is not particularly limited, but is preferably 70% or more, more preferably 80% or more, particularly preferably 90% or more, and most preferably. 99% or more. As the hydrogenation rate increases, the heat resistance of the polymer (β) further improves.

  In the polymer (β), the syndiotactic stereoregularity of the polymer (α) subjected to the hydrogenation reaction is generally maintained. Therefore, the polymer (β) has syndiotactic stereoregularity. The proportion of the racemo dyad in the polymer (β) is not particularly limited as long as the polymer (β) has crystallinity, but is usually 60% or more, preferably 65% or more, and more preferably 70 to 99%. .

The proportion of the racemo dyad in the polymer (β) can be determined by measuring a ¹³ C-NMR spectrum and quantifying it based on the spectrum data. For example, using a mixed solvent of 1,2,4-trichlorobenzene-d3 and orthodichlorobenzene-d4, ¹³ C-NMR measurement was performed at 200 ° C., and a signal of 43.35 ppm derived from meso dyad and racemo. The ratio of the racemo dyad can be determined from the intensity ratio of the 43.43 ppm signal derived from the dyad.

The polymer (β) is a polymer having crystallinity (that is, a film-shaped molded product having a melting point is obtained). The temperature range of the melting point is not particularly limited, but is usually 260 to 275 ° C.
The polymer (β) having such a melting point is more excellent in balance between moldability and heat resistance. The melting point of the polymer (β) can be adjusted by adjusting the degree of syndiotactic stereoregularity (ratio of racemo dyad) or selecting the type of monomer to be used. .

When producing an unstretched film using the polymer (β), as the raw material resin, only the polymer (β) may be used, or a resin composition containing the polymer (β) and an additive may be used. May be used.
As additives, antioxidants such as phenolic antioxidants, phosphorus antioxidants, and sulfur antioxidants; light stabilizers such as hindered amine light stabilizers; petroleum waxes, Fischer-Tropsch waxes, and polyalkylene waxes Sorbitol compounds, metal salts of organic phosphoric acids, metal salts of organic carboxylic acids, nucleating agents such as kaolin and talc; diaminostilbene derivatives, coumarin derivatives, azole derivatives (eg, benzoxazole derivatives, benzotriazole derivatives) , Benzimidazole derivatives, and benzothiazole derivatives), carbazole derivatives, pyridine derivatives, naphthalic acid derivatives, and imidazolone derivatives; fluorescent whitening agents; benzophenone-based ultraviolet absorbers, salicylic acid-based ultraviolet absorbers, and benzotriazole-based ultraviolet absorbers UV absorbers; inorganic fillers such as talc, silica, calcium carbonate, and glass fiber; colorants; flame retardants; flame retardant aids; antistatic agents; plasticizers; Polymer materials other than the polymer (β) such as a polymer;

  When an additive is used, the amount of the additive is not particularly limited as long as the effect of the present invention is not impaired, and can be appropriately determined according to the purpose. The content of these additives contained in the resin composition is usually in the range of 0.001 to 5 parts by weight, preferably 0.01 to 1 part by weight, based on 100 parts by weight of the polymer (β).

The method for producing the unstretched film is not particularly limited, and a known molding method can be appropriately used.
Examples of the molding method include injection molding, extrusion molding, press molding, inflation molding, blow molding, calender molding, cast molding, and compression molding. Among these, the extrusion molding method is preferable because the thickness of the unstretched film is easily controlled.
In the extrusion molding method, the cylinder temperature (molten resin temperature) is usually 250 to 330 ° C, preferably 260 to 310 ° C, and the cast roll temperature is usually 45 to 160 ° C, preferably 45 to 130 ° C. The roll temperature is usually 25 to 150C, preferably 45 to 120C.

  Although the thickness of the unstretched film is not particularly limited, it is generally 1 μm to 1 mm, preferably 10 to 500 μm.

After stretching the unstretched film, heat treatment is performed.
When the unstretched film is stretched, the stretching method is not particularly limited, and a known method can be appropriately used.
As the stretching method, a uniaxial stretching method such as a method of uniaxially stretching in the longitudinal direction using a difference in peripheral speed on the roll side, a method of uniaxially stretching in the lateral direction using a tenter stretching machine, and the like. Simultaneous biaxial stretching method, in which the guide rail is stretched in the horizontal direction at the same time as the guide rail spread angle, or stretching in the vertical direction using the difference in peripheral speed between rolls, then clip both ends A biaxial stretching method such as a sequential biaxial stretching method in which the film is gripped and stretched in the transverse direction using a tenter stretching machine; feeding force, pulling force, or take-off force at different speeds in the horizontal or vertical direction can be added. Continuous oblique stretching in the direction of an arbitrary angle θ with respect to the width direction of the film using a tenter stretching machine;

  The stretching temperature is usually 95 to 135 ° C, preferably 100 to 130 ° C. When the stretching temperature is 95 ° C. or higher, problems such as breakage of the film at the time of stretching and reduction in productivity due to detachment of the clip hardly occur. When the stretching temperature is 135 ° C. or lower, a resin film having a small heat shrinkage can be efficiently produced.

  The stretching ratio is usually 1.2 to 10 times, preferably 1.5 to 5 times. When the stretching ratio is 1.2 times or more, a resin film having a high softening point can be efficiently produced. On the other hand, when the stretching ratio is 10 times or less, a resin film having excellent toughness can be efficiently produced. When the biaxial stretching method is used, the stretching ratio is defined by the product of the vertical and horizontal stretching ratios.

  The stretching speed is usually 100 to 30,000 mm / min, preferably 1,000 to 20,000 mm / min. When the stretching speed is 100 mm / min or more, the resin film (I) having a high softening point can be efficiently produced. On the other hand, when the stretching speed is 30,000 mm / min or less, problems such as breakage of the film at the time of stretching and reduction in productivity due to detachment of the clip hardly occur.

When heating the stretched film obtained by the stretching process, the heating method is not particularly limited, and a known method can be appropriately used.
Examples of the heating method include a method in which the stretched film is fixed on a table and then heated using a heating device such as a heat treatment oven or an infrared heater.

The heating temperature is usually from 150 to 240C, preferably from 160 to 210C. When the heating temperature is in the range of 150 ° C. to 240 ° C., the resin film (I) having a small heat shrinkage can be efficiently produced.
The heating time is usually 0.1 to 600 minutes, preferably 3 to 300 minutes. When the heating time is 0.1 minute or more, the resin film (I) having a small heat shrinkage can be efficiently produced. On the other hand, when the heating time is 600 minutes or less, the resin film (I) having a small tan δ can be efficiently produced.

The thickness of the film obtained as described above is not particularly limited, but is usually 1 to 200 μm, preferably 2 to 150 μm.
A film having a thickness within the above range is preferably used as a dielectric film of a film capacitor.

  As described above, the resin film (I) is obtained by stretching a non-stretched film using a hydrogenated crystalline dicyclopentadiene ring-opening polymer, followed by heat treatment, Softening point is 250-320 ° C, heat shrinkage when heated at 200 ° C for 10 minutes is 0.01-5.0%, tan δ is 0.0001-0.0010, and static friction coefficient is 0.01-1.00. Resin film.

The softening point of the resin film (I) is from 250 to 320 ° C, preferably from 250 to 300 ° C.
If the softening point of the resin film (I) is too low, the coefficient of static friction tends to be high, and the workability when manufacturing a film capacitor tends to be poor. On the other hand, a resin film (I) having a softening point exceeding 320 ° C. is usually difficult to obtain.
The softening point of the resin film (I) can be increased by, for example, increasing the stretching ratio or increasing the stretching speed in the stretching process. Further, by using a polymer (β) having a high ratio of racemo dyad and a high hydrogenation rate, a resin film (I) having a higher softening point tends to be obtained.

The heat shrinkage of the resin film (I) when heated at 200 ° C. for 10 minutes is 0.01 to 5.0%, preferably 0.1 to 4.9%.
The resin film (I) having an excessively large heat shrinkage tends to be inferior in heat resistance. On the other hand, the resin film (I) having a heat shrinkage of less than 0.01% is usually difficult to obtain.
This heat shrinkage can be reduced by, for example, performing a stretching treatment at a stretching temperature that is not too high, or performing a heating treatment at an appropriate temperature for a certain period of time.

The tan δ of the resin film (I) is 0.0001 to 0.0010.
The resin film (I) having a tan δ of more than 0.0010 tends to have poor withstand voltage characteristics. On the other hand, a resin film (I) having a tan δ of less than 0.0001 is usually difficult to obtain.
The tan δ of the resin film (I) can be reduced, for example, by avoiding long-time heating in the heat treatment. Further, by reducing the amount of metal contained as an impurity in the polymer (β), a resin film (I) having a smaller tan δ can be produced.

The coefficient of static friction of the resin film (I) is 0.01 to 1.00, preferably 0.10 to 0.90.
A resin film (I) having a coefficient of static friction of more than 1.00 and a resin film (I) of less than 0.01 tend to be inferior in workability.
The coefficient of static friction of the resin film (I) can be determined by, for example, increasing the stretching ratio, increasing the stretching speed, or performing heat treatment at an appropriate temperature for a certain period of time in the stretching process. , Can be smaller. Further, by using a polymer (β) having a high ratio of racemo / diad and a high hydrogenation rate, a resin film (I) having a small static friction coefficient can be produced.

The resin film (I) having the above characteristics has excellent heat resistance, withstand voltage characteristics and workability.
For example, even when the resin film (I) is heated at 220 ° C. for 10 minutes, shrinkage and softening hardly occur, and the shape is maintained.
Further, when a dielectric breakdown test is performed on the resin film (I), the dielectric breakdown voltage is usually 400 kV / mm or more.
In addition, since the resin film (I) has a moderate coefficient of static friction, the long resin film (I) may be wound into a roll, the resin film (I) may be pulled out from the roll, or may be wound. When manufacturing a film capacitor of a mold, work can be performed efficiently.

  Because of these properties, the resin film (I) is used as a dielectric film material for a film capacitor.

  As the dielectric film made of the resin film (I), a resin film (I) cut into a predetermined size, or a surface treatment such as a corona treatment or a plasma treatment is applied to the surface of the resin film (I). After that, it is cut into a predetermined size.

(Metal layer)
The metal layer constituting the film capacitor of the present invention is not particularly limited, and may be the same as the metal layer (also called an electrode layer) of a conventional film capacitor.
The metal constituting the metal layer is not particularly limited as long as it is a conductive metal, and examples thereof include aluminum, zinc, gold, platinum, and copper.

The metal layer can be formed by using a metal foil of these metals. In addition, a vapor-deposited metal film obtained by vapor-depositing a metal on the surface of the dielectric film [resin film (I)] can be used as the metal layer.
When the metal layer is formed using a metal foil, the thickness of the metal layer is not particularly limited, but is usually 0.1 to 100 μm, preferably 1 to 50 μm, more preferably 3 to 15 μm. Range.
When the metal layer is a vapor-deposited metal film, the thickness of the metal layer is not particularly limited, but is usually in the range of 10 to 200 nm, preferably 20 to 100 nm.

Since a metal layer that is thin and has excellent adhesion to a dielectric film can be efficiently formed, and a smaller and more durable film capacitor can be manufactured, the metal layer is formed of a vapor-deposited metal. Coatings are preferred.
When using a vapor-deposited metal film as the metal layer, the method for forming the vapor-deposited metal film is not particularly limited, and a vacuum vapor deposition method, a sputtering method, an ion plating method, or the like can be appropriately used.
The deposited metal coating may be a single layer or a multilayer. Examples of the multilayered deposited metal film include a deposited metal film described in JP-A-2-250360.

〔Film capacitor〕
The film capacitor of the present invention has the dielectric film and a metal layer.
The structure of the film capacitor of the present invention is not particularly limited as long as the dielectric film is made of the resin film (I).

As the film capacitor of the present invention, a laminated film capacitor in which a dielectric film and a metal layer are alternately laminated (JP-A-63-181411, JP-A-3-18113, etc.); And a wound film capacitor in which a body film and a metal layer are wound (JP-A-60-262414, JP-A-3-286514, etc.).
The method for manufacturing these film capacitors is not particularly limited, and a conventionally known method can be used.

The film capacitor of the present invention has a resin film having excellent heat resistance, withstand voltage characteristics, and workability as a dielectric film.
Therefore, the film capacitor of the present invention, even if small, has excellent heat resistance and durability, and hardly produces defective products even when produced on an industrial scale.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. Note that the present invention is not limited to these examples. In the following, “parts” and “%” are based on weight unless otherwise specified.

Various physical properties were measured according to the following methods.
(1) Molecular weight (weight average molecular weight and number average molecular weight) of dicyclopentadiene ring-opened polymer
The molecular weight of the ring-opened polymer of dicyclopentadiene was measured by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent, and determined as a standard polystyrene equivalent value.
The measurement was performed at 40 ° C. using a system HLC-8320 (manufactured by Tosoh Corporation) as a measuring device and an H type column (manufactured by Tosoh Corporation) as a column.

(2) Hydrogenation rate of hydrogenated dicyclopentadiene ring-opening polymer
¹ H-NMR measurement was performed to determine the hydrogenation rate of the hydrogenated dicyclopentadiene ring-opening polymer.

(3) Ratio of racemo dyad of hydrogenated dicyclopentadiene ring-opening polymer Using an insegated decoupling method using a mixed solvent of 1,2,4-trichlorobenzene-d3 and orthodichlorobenzene-d4, A ¹³ C-NMR measurement was performed at 200 ° C., and a signal of 43.35 ppm derived from meso dyad and a signal of 43.43 ppm derived from racemo dyad were determined with the peak of 127.5 ppm of orthodichlorobenzene-d4 as a reference shift. Based on the strength ratio, the ratio of racemo dyad of the hydrogenated dicyclopentadiene ring-opening polymer was determined.

(4) Softening point of resin film The obtained resin film was cut out at an arbitrary site into a circular shape having a diameter of 5 mm to obtain a measurement sample. The obtained measurement sample was heated under a heating condition of 10 ° C./min using a thermomechanical analyzer (SS6100, manufactured by Hitachi High-Tech Science), and the softening point of the resin film was measured.

(5) Thermal Shrinkage of Resin Film The obtained resin film was cut into a square of 500 mm × 500 mm at an arbitrary position to obtain a measurement sample. At this time, each side of the square was made to coincide with the flow direction (MD direction) and the width direction (TD direction) during the production of the resin film.
The obtained measurement sample was heated at 200 ° C. for 10 minutes using an oven, and the amount of change in the length in the MD and TD directions before and after heating was examined, and the heat shrinkage of the resin film was calculated. The heat shrinkage is an average value in the MD and TD directions.

(6) Dielectric loss tangent (tan δ) of resin film
The obtained resin film was cut into a size of 150 mm × 1 mm at an arbitrary position to obtain a measurement sample. With respect to the obtained measurement sample, tan δ at a frequency of 1 GHz was measured using a network analyzer (N5230A, manufactured by Agilent).

(7) Static friction coefficient of resin film The static friction coefficient between the resin film and the ball indenter was measured according to ASTM D1894 using a tribogear surface property measuring device (TYPE38, manufactured by Shinto Kagaku). The load was 200 g, and the speed was 100 mm / mm.

(8) Heat Resistance of Resin Film The obtained resin film was cut into a square of 500 mm × 500 mm at an arbitrary place to obtain a measurement sample.
The obtained measurement sample was heated at 220 ° C. for 10 minutes using an oven, the shape of the measurement sample after heating was visually observed, and the heat resistance of the resin film was evaluated based on the following criteria.
：: The shape of the measurement sample was maintained before and after heating.
×: A shape change due to heat shrinkage or softening was observed after heating.

(9) Withstand voltage characteristics of resin film (measurement of dielectric breakdown voltage)
About the obtained resin film, the dielectric breakdown voltage was measured using the dielectric breakdown voltage measuring device (YST-243-100RHO manufactured by Yamayo Test Instruments Co., Ltd.), and the withstand voltage characteristics of the resin film were examined.

(10) Workability of resin film Two obtained resin films were stacked, and a weight of 100 g was put thereon. The appearance when one of the resin films was slid horizontally at a speed of 10 mm / sec was observed, and the workability of the resin film was evaluated based on the following criteria.
：: Only the slid resin film moved without resistance.
X: Feel resistance or two films moved simultaneously.

[Production Example 1]
154.5 parts of cyclohexane and 42.8 parts of a cyclohexane solution (concentration: 70%) of dicyclopentadiene (end body content of 99% or more) in a metal pressure-resistant reaction vessel whose inside is purged with nitrogen (the amount of dicyclopentadiene is 30) Parts) and 1.9 parts of 1-hexene, and the whole was stirred and heated to 53 ° C.
On the other hand, 0.061 part of a diethyl aluminum ethoxide / n-hexane solution (concentration: 19%) was added to a solution of 0.014 part of tetrachlorotungstenphenylimide (tetrahydrofuran) complex dissolved in 0.70 part of toluene. The mixture was stirred for 10 minutes to prepare a catalyst solution.
While stirring the contents of the reactor, this catalyst solution was added into the reactor to start the ring-opening polymerization reaction, and thereafter, the ring-opening polymerization reaction was performed for 4 hours while keeping the whole volume at 53 ° C. Next, 0.037 parts of 1,2-ethanediol was added as a terminator into the reactor, and the whole volume was heated to 60 ° C. and stirred for 1 hour to terminate the polymerization reaction.
The number average molecular weight (Mn) and weight average molecular weight (Mw) of the ring-opened dicyclopentadiene polymer in the obtained reaction solution were 8,750 and 28,100, respectively, and the molecular weight distribution (Mw / Mn) was 3.21.

To the reaction solution, 1 part of a hydrotalcite-like compound (Kyowa (registered trademark) 2000, manufactured by Kyowa Chemical Industry Co., Ltd.) was added as an adsorbent, heated to 60 ° C., and stirred for 1 hour. To this, 0.4 parts of a filter aid (Radiolite (registered trademark) # 1500, manufactured by Showa Chemical Industry Co., Ltd.) was added, and then a PP pleated cartridge filter (ADVANTEC Toyo, TCP-HX) was used. The adsorbent was removed by filtration.
To 200 parts of the dicyclopentadiene ring-opening polymer solution after filtration (polymer amount: 30 parts), 100 parts of cyclohexane and 0.0043 part of chlorohydridocarbonyltris (triphenylphosphine) ruthenium were added, and the hydrogen pressure was 6 MPa and the temperature was 180 ° C. For 4 hours. In the obtained hydrogenation reaction solution, a polymer was precipitated to form a slurry solution.
This slurry liquid was subjected to a centrifugal separation treatment to separate the hydrogenated dicyclopentadiene ring-opening polymer from the solution, and the hydrogenated dicyclopentadiene ring-opening polymer was collected by filtration. Next, this was dried under reduced pressure at 60 ° C. for 24 hours to obtain 28.5 parts of a hydrogenated dicyclopentadiene ring-opening polymer having crystallinity.
The hydrogenation rate of the hydrogenated dicyclopentadiene ring-opening polymer was 99% or more, the melting point (Tm) was 262 ° C., and the ratio of racemo dyad was 89%.

[Production Example 2]
As an antioxidant, tetrakis [methylene-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) was added to 100 parts of the hydrogenated dicyclopentadiene ring-opening polymer obtained in Production Example 1. ) Propionate] methane (Irganox (registered trademark) 1010, manufactured by BASF Japan) was mixed with 1.1 parts to obtain a raw material composition. This raw material composition is put into a twin-screw extruder (TEM-37B, manufactured by Toshiba Machine Co., Ltd.) having four die holes having an inner diameter of 3 mm, and a strand-shaped molded body is obtained by a hot-melt extrusion molding method. After cooling, the mixture was chopped with a strand cutter to obtain resin pellets.

The operating conditions of the twin-screw extruder are shown below.
-Barrel set temperature: 270-280 ° C
・ Die setting temperature: 270 ℃
-Screw rotation speed: 145 rpm
・ Feeder rotation speed: 50 rpm

[Production Example 3]
Using the resin pellets obtained in Production Example 2, a film having a thickness of 150 μm and a width of 120 mm was formed on a hot melt extrusion film forming machine equipped with a T-die (manufactured by Optical Control Systems, Measurement Extruder Type Me-20 / 2800 V3). The obtained unstretched film was wound into a roll at a speed of 2 m / min.

The operating conditions of the film forming machine are shown below.
・ Barrel temperature setting: 280-290 ° C
・ Die temperature: 270 ℃
-Screw rotation speed: 30 rpm

[Example 1]
After the unstretched film obtained in Production Example 3 was cut into a 90 mm × 90 mm square at an arbitrary position, it was set on a small stretching machine (EX10-B type, manufactured by Toyo Seiki Seisaku-sho, Ltd.), and the stretching temperature was: The film was stretched under the conditions of 100 ° C., stretching ratio: 2.0 × 2.0, and stretching speed: 10,000 mm / min.
Next, the obtained stretched film was fixed on an iron plate, and this was heat-treated at 200 ° C. for 20 minutes using an oven to obtain a resin film for a dielectric film.
Various measurements were performed on the obtained resin film for a dielectric film. Table 1 shows the measurement results.

[Example 2]
Except that in Example 1, the stretching treatment was performed by changing the stretching ratio to 3.0 × 3.0 times and the stretching speed to 300 mm / min, and then further performing the heating treatment by changing the heating temperature to 210 ° C. In the same manner as in Example 1, a resin film for a dielectric film was obtained, and various measurements were performed on the obtained resin film for a dielectric film. Table 1 shows the measurement results.

[Example 3]
A resin film for a dielectric film was produced in the same manner as in Example 1 except that the stretching treatment was performed by changing the stretching temperature to 130 ° C. and the heating treatment was further performed by changing the heating temperature to 150 ° C. Various measurements were performed on the obtained and obtained resin film for a dielectric film. Table 1 shows the measurement results.

[Example 4]
In Example 1, a resin film for a dielectric film was obtained in the same manner as in Example 1, except that the heat treatment was performed by changing the heating time to 5 minutes. A measurement was made. Table 1 shows the measurement results.

[Example 5]
Example 1 is the same as Example 1 except that the stretching treatment was performed by changing the stretching ratio to 1.5 × 1.5, and the heating temperature was changed to 230 ° C. and the heating time was changed to 100 minutes. A resin film for a dielectric film was obtained in the same manner as in Example 1, and various measurements were performed on the obtained resin film for a dielectric film. Table 1 shows the measurement results.

[Comparative Example 1]
In Example 1, a resin film was obtained in the same manner as in Example 1 except that the stretching treatment was performed while changing the stretching temperature to 140 ° C., and various measurements were performed on the obtained resin film. Table 1 shows the measurement results.

[Comparative Example 2]
In Example 1, a resin film was obtained in the same manner as in Example 1 except that the stretching treatment was performed by changing the stretching ratio to 1.1 × 1.1, and various measurements were performed on the obtained resin film. Was done. Table 1 shows the measurement results.
In this resin film, crystallization did not proceed sufficiently, and the softening point was too low. For this reason, the heat shrinkage could not be measured.

[Comparative Example 3]
In Example 1, a resin film was obtained in the same manner as in Example 1 except that the stretching treatment was performed while changing the stretching speed to 80 mm / min. Various measurements were performed on the obtained resin film. Table 1 shows the measurement results.
In this resin film, crystallization did not proceed sufficiently, and the softening point was too low. For this reason, the heat shrinkage could not be measured.

[Comparative Example 4]
In Example 1, a resin film was obtained in the same manner as in Example 1 except that the heat treatment was performed by changing the heating temperature to 250 ° C., and various measurements were performed on the obtained resin film. Table 1 shows the measurement results.

[Comparative Example 5]
In Example 1, a resin film was obtained in the same manner as in Example 1 except that the heat treatment was performed at a heating temperature of 140 ° C., and various measurements were performed on the obtained resin film. Table 1 shows the measurement results.

[Comparative Example 6]
In Example 1, a resin film was obtained in the same manner as in Example 1, except that the heating time was changed to 0.05 minutes, and various measurements were performed on the obtained resin film. Table 1 shows the measurement results.

[Comparative Example 7]
In Example 1, a resin film was obtained in the same manner as in Example 1, except that the heating time was changed to 700 minutes, and various measurements were performed on the obtained resin film. Table 1 shows the measurement results.

Table 1 shows the following.
The resin films obtained in Examples 1 to 5 are excellent in heat resistance, withstand voltage characteristics, and workability.
On the other hand, the resin films obtained in Comparative Examples 1, 4 to 6 have a large heat shrinkage and are inferior in heat resistance.
The resin films obtained in Comparative Examples 2 and 3 have low softening points, and these resin films also have poor heat resistance.
The resin films obtained in Comparative Examples 2, 3, 5, and 6 have a large coefficient of static friction and are inferior in workability.
The resin film obtained in Comparative Example 7 has a large tan δ and is inferior in withstand voltage characteristics.

Claims (1)

A film capacitor having a dielectric film and a metal layer,
The dielectric film,
An unstretched film using a hydrogenated crystalline dicyclopentadiene ring-opening polymer is stretched at a stretching temperature of 95 to 135 ° C, a stretching ratio of 1.2 to 10 times, and a stretching speed of 100 to 30,000 mm / min. After stretching under the following conditions , the heating temperature is 150 to 240 ° C., and the heating time is 0.1 to 600 minutes .
The resin film has a softening point of 250 to 320 ° C., a heat shrinkage of 0.01 to 5.0% when heated at 200 ° C. for 10 minutes, a tan δ of 0.0001 to 0.0010, and a static friction coefficient of 0.1. A film capacitor comprising a resin film of No. 01 to 1.00.